Consequently, the manufacturers of terminals are constantly improving their capacities by adding ever more powerful processing means, higher-capacity memories, screens of better definition etc. This is leading to an increase in the complexity, weight and above all the cost of the terminals.
Furthermore, mechanisms for graphic display forwarding have been proposed in which a server asks the customer known as a “thin” customer to execute display operations, on its behalf, on a screen. These graphic display forwarding mechanisms enable execution of programs that contain simplified graphic interfaces on a computer and restitute the display of these programs on a remote terminal.
This approach, which is the one used by the X-Windows (registered mark) system especially has a classic customer/server architecture used for the display, on an X terminal, of applications working in any host system or application server whatsoever. The application server comprises a customer application and a customer library for communications with the X server.
The remote terminal (X terminal) must have, at the minimum, capacities for management of applications windows (X server) and a video driver carrying out displays of windows on the terminal. The information coming from the application server is restituted after processing for display by the remote terminal. The information exchanges are done on a standard network by means of the TCP/IP communications protocol.
One drawback of this prior art technique is that these display forwarding mechanisms are not suited to the ultra-thin terminals (for example a home telephone or remote control unit) having very limited information-processing capacities and no advanced software environments. Indeed, in order to function, an Xterminal, such as the one referred to here above, requires a non-negligible minimum hardware configuration to enable it to execute the software programs such as an Xserver or its equivalent.
Another drawback of these prior art techniques is that the software cannot be fragmented within the communications terminal. The software program must be integrally present so that the terminal can process the information that comes to it.
Another drawback of this prior art technique is related to the limitation of the bandwidth. Indeed, to display data from the remote application, the terminal must receive a major volume of information resulting in either the congestion of the communications network used to transmit information or in it's becoming technical impossible for the remote terminal to take charge of the information transmitted to it.
To overcome these prior art drawbacks, methods have been set up, for example the creation of buffering (proxy) used to store information coming from the server while the terminal has time needed to process the information it has already received. Certain methods also consist of an improvement of the communications protocols used or an increase in the capacities of the remote communications terminal. These specific methods however add further to the complexity of the system.
Yet another drawback of these prior art techniques is that the display performances, especially the speed and fluidity of the applications working on the terminal, are strongly linked to the capacities of the graphic devices contained in the terminal.
These drawbacks are reinforced in remote communications because, in certain places and/or in certain situations, the infrastructure of the information transmission channels does not provide for efficient information processing even if, in absolute terms, the terminal allows it.
Finally, these techniques remain complex and costly and imply firstly a specific infrastructure and, secondly, techniques that use fairly heavy means.